Accelerating the menaquinone‑7 production in Bacillus amyloliquefaciens by optimization of the biosynthetic pathway and medium components  

作　　者：Chang‑Long Li Meng Li Wei‑Guo Zhang Jian‑Zhong Xu 

机构地区：[1]The Key Laboratory of Industrial Biotechnology,Ministry of Education,School of Biotechnology,Jiangnan University,1800#Lihu Road,WuXi 214122,People’s Republic of China

出　　处：《Systems Microbiology and Biomanufacturing》2023年第4期776-791,共16页系统微生物学与生物制造（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(no.32271534);the National Key Research and Development Program of China(2021YFC2100900);the Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions,the 111 project(Grant number 111-2-06).

摘　　要：Menaquinone-7(MK-7)has an important role in preventing diseases such as cardiovascular disease and osteoporosis.In this study,a combination strategy of strain improvement and medium optimization is investigated to increase MK-7 production in Bacillus amyloliquefaciens.Conventional breeding method was first used to modify the biosynthetic pathway to construct a MK-7 high-producing strain by atmospheric and room temperature plasma mutagenesis and protoplast fusion.The resulted strain Ba-4 with resistance to sulfaguanidine,1-hydroxy-2-naphthoic acid,menadione,2-deoxy-d-glucose and rifampicin as well as sensitive toβ-fluoropyruvate produced 73.57±1.61 mg/L of MK-7,which was 1.36 times more than that of the parent strain H.β.D.R.-5(i.e.,31.12±1.40 mg/L).Subsequently,single-factor optimization and response surface method-ology(RSM)were used to optimize the medium components for increasing MK-7 production by strain Ba-4.Strain Ba-4 produced 90.43±1.32 mg/L of MK-7 under the single-factor optimized medium.Moreover,the results of response surface methodology indicated that glycerol,soy peptone and Tween-80 had significant effects on MK-7 production,and the highest MK-7 production(i.e.,95.03±1.01 mg/L)was obtained under the optimized medium,which was 0.29 times higher than that of the initial medium.These results confirmed that the conventional breeding methods and fermenter control system are effective strategies in improving MK-7 production by B.amyloliquefaciens.

关 键 词：Bacillus amyloliquefaciens Menaquinone-7 ARTP mutagenesis system Protoplast fusion Medium optimization 

分 类 号：Q93[生物学—微生物学]